The present invention relates to a product containing a healthful or salutary component and a process for preparing the same. In particular, the product of the present invention is prepared from a pulse crop as a starting material. The term xe2x80x9cpulse cropxe2x80x9d used herein means leguminous crops such as soybeans, defatted products and hycopotyls thereof, soy protein extracts, soy protein isolates and so forth, and the term xe2x80x9cproductxe2x80x9d means products as such (plain products) which are made from a pulse crop as a starting material, applied products containing the plain product as an ingredient, for example, foods, livestock feeds and aquacultural feeds, cosmetics, diets of pets, and precursory products for pharmaceutical preparations.
In general, soybean, which is one of the pulse crops, contains isoflavone compounds including daidzin, daidzein, genistin and genistein.
The isoflavone compounds are represented by the following formula and Denotative Table. 
Of these isoflavone compounds, daidzein is an aglycone of daidzin having its glucose as a glycosidic saccharide hydrolytically separated therefrom, and genistein is an aglycone of genistin having its glucose as a glycosidic saccharide hydrolytically separated therefrom. With respect to the isoflavone compounds, contents thereof and percentages between daidzin and daidzein and between genistin and genistein in a defatted soybean are shown in the following Table 1.
It is understood from Table 1 that, in soybeans, daidzin and genistin are contained in large amounts while daidzein and genistein which are aglycones thereof are contained in smaller amounts.
On the other hand, it has been reported that a glycosidic saccharide is hydrolyzed from an isoflavone compound contained in soybeans to form an aglycone in the course of soy sauce or miso (fermented soybean paste) preparation [see Kihara, K.: Journal of Japan Soy Sauce Research Institute (for SHO-KEN), 16, 5, 190(1990)].
According to this report, although hydrolysis of a glycosidic saccharide proceeds to some extent in cooking of a defatted soybean or in a koji preparation step (seigiku step), most of the saccharide has already hydrolytically been separated in soy sauce cake or a soybean miso. However, since these are highly salinized, ingesting these in large quantities should be avoided. Accordingly, it is difficult to employ any process for preparing these as a process for preparing a food from a pulse crop as a starting material.
Soyasaponins occur in soybeans. For example, in a defatted soybean, soyasaponins occur in an amount of 500 to 700 mg/100 g. It has been reported that soyasaponins consist of 5 varieties of saponins, i.e., soya saponin I, soya saponin II, soya saponin III, soya saponin A1 and soya saponin A2 in the form of a mixture [see Kitagawa et al.: YAKUGAKU ZASSHI, 104, 2, 162-168(1984)]. Each of these has glucuronic acid as a glycosidic saccharide, and the aglycone which is such a compound that the glycosidic saccharide is removed therefrom includes two varieties of soyasapogenol A and soyasapogenol B. In general, however, the aglycone is present as soyasapogenol B. In a commercially. available soybean miso, however, neither soyasapogeriol A nor soyasapogenol B was detected.
Further, many reports have been made on pharmacological activities of various constituents contained in pulse crops.
For example, a Pueraria lobata Ohwi (kudzu), which is a type of legume, has been used for a long time as a material for an infusion of Pueraria root (Puerariae Radix) as an herb medicine. It has been reported that isoflavone compounds and saponins contained in Pueraria root have liver function improving effects (therapeutic activities against hepatopathy) [see xe2x80x9cNohara et al.: Journal of Medical and Pharmaceutical Society (for WAKAN-YAKU),. 5, 408-409(1988xe2x80x9d, xe2x80x9cY. Niiho et al.: YAKUGAKU ZASSHI., 109, 6, 424-431(1989)xe2x80x9d and xe2x80x9cY. Niiho et al.: YAKUGAKU ZASSHI., 110, 8, 601-611(1990)xe2x80x9d]. More specifically, an alcohol concentration, an acetaldehyde concentration and a concentration of ketones in blood can be lowered to prevent hangovers, nasty aftereffects of drinking or the like, and metabolic dysfunction of the liver can be prevented. Further, it has been reported that soyasaponins contained in soybeans have an anti-inflammatory effect, and can reduce serum cholesterol, neutral fats and phospholipids (cardiac function improving, lipotropic, antidiabetic, antifat, and flesh reducing effects) as well as the above-described effect in common with pueraria root [see Ohminami et al.: EIYO TO SHOKURYO., 34, 2, 105-108(1981)]. It is said that although soyasaponins have the effect of improving functions of a living body as described above, soyasaponins in the form of a glycoside can not be absorbed in a body. Accordingly, saponins in the form of a glycoside are not intestinally absorbable until they are decomposed into an aglycone, i.e., soyasapogenol B by enterobacteria having xcex2-glucuronidase effect. It is said that the decomposition takes a lot of time and thus the aglycone has little chance of being absorbed by a small intestine to lead to an extremely low absorption efficiency. On the other hand, the enterobacteria having xcex2-glucuronidase effect is not regarded as useful enterobacteria. Accordingly, placing no reliance on the decomposition by the enterobacteria, it is desired that soyasaponins be preliminarily decomposed in vitro into soyasapogenol B to ingest the latter. The same desire is true of the soy isoflavone compounds.
Further, soyasapogenol B is a triterpene compound and effective as an endotherine (ET) converter enzyme inhibitor (see Japanese Patent Application Laid-Open (Kokai) No. H7(1995)-188033) and inhibits an endotherine converter enzyme from exhibiting its function, and hence soyasapogenol B is effective as a remedy for endotherine (ET)-related disorders such as hypertension, cerebrovascular contraction after subarachnoid hemorrhage, myocardial infarction, arteriosclerosis, heart failure,renal failure, asthma, and so forth. Further, the triterpene compound has a lipase inhibitory effect and a glycerophosphate dehydrogenase inhibitory effect. Accordingly, the triterpene compound is capable of inhibiting the decomposition of lipids to prevent the lipids from being absorbed in a body, and thus, it is effective for the prevention and treatment of obesity (see Japanese Patent Application Laid-Open (Kokai) Nos. H9(1997)-40689 and H9(1997)-67249) and expected to improve cardial functions and to reduce flesh. Therefore, it is desired that soyasaponins be decomposed to obtain soyasapogenol B as an aglycone of saponins.
Moreover, it has been reported that free myo-inositol and the like, which are formed by the decomposition of phytic acid in soybeans, have a liver function improving effect of facilitating lipometabolism in a liver (therapeutic activities against hepatopathy) (see Kubota, H.: FOOD CHEMICAL, 8, 83-89 (1987).
A further description will be made on promoting liver functions. It has been reported that miso soup has an anti-cancer effect, and this is because the enzyme activity of a liver is enhanced by the ingestion of miso soup [see Kanke, S.: SHOKU NO KAGAKU, 224, 50-54(1996)]. More specifically, it is reported that when iron as a carcinogen and oxidant and miso are fed to a rat or mouse, glutathione-s-transferase (GST) activity is increased. GST has been known to combine a carcinogen with glutathione to form a glutathione conjugate, which is excreted from a body. It is said that phase II xenobiotic-metabolizing enzymes to enhance carcinogen detoxication and elimination such as NAD(P)H: quinone oxidoreductase (DT diaphorase) and aldehyde dehydrogenase, as well as conjugating enzymes such as GST and UDP-glucuronosyl-transferase.
Accordingly, many proposals concerning isoflavone compounds contained in soybeans are disclosed in Japanese Patent Application Laid-Open (Kokai) Nos. S62(1987)-126186, H1(1989)-258669, H5(1993)-170756, and so on.
According to the process described in Japanese Patent Application Laid-Open (Kokai) No. S62(1987)-126186, however, most of the resulting isoflavone compounds are daidzin and genistin which each has a glycosidic saccharide, and aglycones are contained in the resultant in small amounts. Thus, it is impossible to obtain foods and the like which have an excellent pharmacological effect as described above.
The process in Japanese Patent Application Laid-Open (Kokai) No. H1(1989)-258669 comprises hydrolytically separating a glycosidic saccharide from an isoflavone compound by the action of xcex2-glucosidase which is one of the enzymes contained in soybeans. However, aglycones are formed in a small proportion.
The process described in Japanese Patent Application Laid-Open (Kokai) No. H5(1993)-170756 is one which comprises extractively separating isoflavone compounds from aglycones of the isoflavone compounds formed in soy sauce cake or soy sauce. Although the aglycones of the isoflavone compounds are formed in the course of soy sauce preparation in a very high proportion as described above, there is the following disadvantage. That is, the aglycones of the isoflavone compounds are present in soy sauce cake because of their insolubility, and soy sauce cake per se does not serve as a food. Accordingly, the process cannot be employed as a process for preparing a food. Further, aglycones of isoflavone compounds are also formed in a soybean miso at the initial stage of preparation. However, soybean miso has a problem in that it is a highly salinized food and therefore ingesting soybean miso in large quantities should be avoided.
With respect to a soybean miso (mame miso), a rice miso (kome miso), Daitokuji Soy nuggets (Daitokuji-natto: a Japanese fermented soy-food in the form of nuggets), dried-frozen tofu (Kori-tofiuxe2x80x94tofu: a Japanese food made of soy milk curds) and yuba (yuba: a Japanese food made of a film which forms on a surface of thick soy milk when the soy milk is gently heated) as commercially available foods made from a pulse crop as a starting material, contents of daidzin and daidzein and contents of genistin and genistein were comparatively measured. The results are as shown in the following Table 2.
It is understood from Table 2 that in the soybean miso, the rice miso and the Daitokuji-natto each of which has been subjected to fermentation treatment, daidzin and genistin have substantially been hydrolyzed, and in particular, the soybean miso and the Daitokuji-natto contain daidzein and genistein which are aglycones of daidzin and genistin in large amounts. However, soybean miso and Daitokuji-natto should not be ingested in large amounts because of their high salt contents. It is also understood that in the dried-frozen tofu, each of daidzin, daidzein, genistin and genistein is contained in a small amount. It is further understood that similarly to the defatted soybean described above, the yuba contains daidzin and genistin in large amounts and daidzein and genistein which are aglycones thereof in small amounts.
Furthermore, when we look at soybean food products of other countries, xe2x80x9ctempeh,xe2x80x9d which is a traditional fermented soybean food product of Indonesia, is a product prepared by fermentation using filiform bacteria of the genus Rhizopus following fermentation by lactic acid bacteria without the addition of salt. This product is used as a raw material for various types of side dishes; however, since absolutely no hydrolysis process is performed on the products produced by the koji preparation process following said koji preparation treatment as in the present invention, it has been reported together with the data shown in FIGS. 4(a) through 4(c) that the rate of aglyconization in which the isoflavone compounds daidzin and genistin contained in soybeans are converted into daidzein and genistein (which are aglycones from which the respective glycosides have been separated) is extremely low compared to that of the above-described miso, etc. (Esaki, H. et al.: ACS Symposium Series 546 xe2x80x9cFood Phytochemical for Cancer Prevention Ixe2x80x9d (1994) 353-360). Accordingly, aglycones constituting health-promoting components cannot be produced more efficiently and in higher concentrations by means of the xe2x80x9ctempehxe2x80x9d.
With respect to a soybean miso (mame miso), a rice miso (kome miso), Daitokuji Soy nuggets (Daitokuji-natto: a Japanese fermented soy-food in the form of nuggets), dried-frozen tofu (Kori-tofu, tofu: a Japanese food made of soy milk curds) and yuba (yuba: a Japanese food made of a film which forms on a surface of thick soy milk when the soy milk is gently heated) as commercially available foods made from a pulse crop as a starting material, phytic acid contents were measured. The results are as shown in Table 3 below.
It is seen from this Table 3 that phytic acid is almost completely broken down in soybean miso, rice miso and Daitokuji natto, which are subjected to fermentation treatments. However, soybean miso, rice miso and Daitokuji natto have high salt concentrations, and cannot be eaten in large amounts. Furthermore, it is seen that the phytic acid content is large in the case of frozen tofu and dried tofu, so that myo-inositol cannot be digested and absorbed.
Furthermore, in regard to other pharmacological actions, soybeans in particular (among various types of beans) consist chiefly of protein, and miso and soy sauce are famous as food products in which this protein is broken down into peptides and amino acids by the protease of koji organisms. Moreover, in such miso and soy sauce, it is claimed that a chemical reaction (Maillard reaction) takes place with carbohydrates and fats which are components of the same soybeans as a result of a drop in the molecular weight of the protein, so that browning and fragrant aromas (aroma of ripening) are produced. In recent research concerning such Maillard reaction products, it has been reported that intermediate Amadori rearrangement products and brown melanoidin or AGE (advanced glycation end product), which are final products, are produced, and that these components are anti-mutagenic substances (Hiromich Kato: Miso no Kagaku to Gijutsu, Vol. 41, No. 2, 40-48 (1993)). However, the following problem arises: i e., miso and soy sauce are food products with a high salt content and cannot be eaten in large amounts.
If it were possible to ingest large amounts of a food product containing large amounts of products including health-promoting components with a superior pharmacological effect such as those described above, it would be possible to enjoy a diet exhibiting superior effects in terms of health maintenance in humans. Conventionally, however, there has been no food product which satisfies such a demand.
In particular, components which latently contain health-promoting components such as the above-described isoflavones, saponins or phytic acid, etc., either contain glycosides as in isoflavones and saponins, or form chelate bonds as in phytic acid. Accordingly, such components tend not to be absorbed by single-stomached animals including human beings or the gastrointestinal digestive tracts of animals; and hepatic function, etc., cannot be improved regardless of the amounts of such components that are ingested.
Conventionally, furthermore, it has been impossible to convert isoflavones, saponins or phytic acid, etc. into forms that are easily digested and absorbed.
The present invention has been made in light of the these points, and the object is to provide a product containing a health-promoting component that includes at least one member of the group consisting of liver function improving constituents, cardiac function improving constituents, anti-inflammatory constituents, antifat constituents, antioxidation consititents and antimutagen constituents; to provide applied products that contain the above-described product, as an ingredient, such as foods which can be ingested in a large amount, livestock feeds, diets of pets and precursory products for pharmaceutical preparations; and further to provide a process for readily preparing the above-described product in a large amount at a low cost.
Another object of the present invention is to provide a process for preparing a product that contains, in addition to the above-described health-promoting component, a health-promoting component which also contains large quantities of bacteria that have an intestine-regulating effect (hereafter referred to as xe2x80x9cintestine-regulating bacteriaxe2x80x9d) in single-stomached animals. Here, the term xe2x80x9csingle-stomached animalsxe2x80x9d refers to animals which do not have a ruminant stomach such as human beings, pets such as dogs and cats, etc., livestock such as horses and pigs, etc., and birds, etc.
In order to accomplish the object, the product of the present invention containing the health-promoting component claimed in claim 1 is characterized in that: the product contains a health-promoting component produced by inoculating koji mold on a pulse crop to effect koji preparation, and then hydrolyzing the products produced by this koji preparation treatment, and the product contains a health-promoting component consisting of intestine-regulating bacteria added to the beans and grown during the period extending from the inoculation of the koji mold to the completion of the hydrolysis.
Furthermore, the process of the present invention for preparing a product that contains the health-promoting component claimed in claim 6 is characterized in that: the health-promoting component is produced by inoculating koji mold on a pulse crop to effect koji preparation, and then hydrolyzing (through the addition of water) the products produced by this koji preparation treatment, and the product that contains the health-promoting component is produced by adding intestine-regulating bacteria which constitute a health-promoting component to the beans and growing the bacteria during the period extending from the inoculation of the koji mold to the completion of the hydrolysis.
The above-described intestine-regulating bacteria are characterized in that they are added at the same time as the inoculation of the koji mold and consist of lactic acid bacteria which have an intestine-regulating effect in single-stomached animals. These intestine-regulating bacteria, and especially lactic acid bacteria, have a good compatibility with the koji mold used in koji preparation, and also propagate very well on their own without interfering with the propagation of the koji mold, so that production efficiency is also superior.
More specifically, koji mold have the property of being able to coexist compatibly with lactic acid bacteria, etc. Accordingly, in the present invention, an effect in which koji mold and lactic acid bacteria are caused to be co-present on a substrate consisting of beans (via a process involving the co-presence and co-growth of koji mold and lactic acid bacteria) is utilized to produce a food product having an object of health maintenance of intestine-regulation functions, etc. in humans and animals.
Yogurt may be cited as an example of a healthy food product utilizing lactic acid bacteria; however, yogurt is not a food product which utilizes koji mold.
The fact that koji mold can co-exist and be co-grown compatibly with lactic acid bacteria, etc., has also been utilized in the past; however, this utilization has been limited to the production of refined sake, shochu, miso and soy sauce, etc., as fermented products, utilizing koji mold.
First, in refined sake, lactic acid bacteria are added in order to cause the growth of large quantities of only sake-refining yeast which has a strong activity in the initial stage. This process is called xe2x80x9cyamahai-motoxe2x80x9d, a traditional Japanese term; here, lactic acid bacteria are naturally admixed and these lactic acid bacteria produce lactic acid, so that an action. which suppresses the propagation of organisms (film yeast, wild yeast, etc.) that are a problem in the manufacture of high-quality refined sake, is utilized. Today, a process in which lactic acid is added (xe2x80x9ctokujo motoxe2x80x9d or rapid fermentation) has also been developed.
Meanwhile, in the manufacture of sake, lactic acid bacteria known as xe2x80x9chiochiixe2x80x9d bacteria which grow with a preference for alcohol cause changes such as cloudiness, an increase in acid and changes in fragrance, etc., and are therefore rather considered to be a problem. It has been found that such xe2x80x9chiochiixe2x80x9d bacteria are lactic acid bacteria that require mevalonic acid. It has been confirmed that such mevalonic acid is caused to accumulate with the propagation of organisms in the koji preparation step by koji mold such as Aspergillus oryzae, etc. Incidentally, it is claimed that lactic acid bacteria that require this mevalonic acid commonly include bacteria that produce bacteriocin.
Furthermore, in miso and soy sauce, lactic acid bacteria are used as a countermeasure to inhibit the growth of undesirable organisms in the aging process.
Thus, products utilizing koji mold are respective products obtained via processes involving the co-presence and co-growth of koji mold and lactic acid bacteria or yeast. However, there has been no food product consisting of a fermented food having an object of health maintenance (e.g., intestine-regulating action, etc.) in humans and animals obtained by utilizing an effect which causes the co-presence and co-growth of koji mold and lactic acid bacteria on substrate grains as in the present invention.
The above-described health-promoting component produced by the koji preparation treatment and hydrolysis treatment are characterized so as to be comprised of at least one member of the group consisting of liver function improving constituents, cardiac function improving constituents, anti-inflammatory constituents, antifat constituents, antioxidation consititents and antimutagen constituents; and it is further characterized in that said component is formed so as to be absorbed by the digestive tract.
According to the process of the present invention, a health-promoting component can be produced in a product using beans as a raw material by means of a koji preparation treatment and a hydrolysis treatment. Furthermore, intestine-regulating bacteria which are added following the initiation of the koji preparation treatment but prior to the completion of the hydrolysis treatment can be propagated, so that the health-promoting component consisting of such intestine-regulating bacteria can also be included in large amounts.
In concrete terms, proteins, isoflavones, saponins and phytic acid, etc., are respectively converted into the health-promoting component such as peptides, isoflavone aglycones, saponin aglycones, myo-inositol and Maillard reaction products, etc., by performing a koji preparation treatment and a hydrolysis treatment on beans used as a raw material, and are thus converted into a state in which these components can be very easily absorbed by the digestive tracts of single-stomached animals, etc. Using the product of the present invention which has such a health-promoting component based on the above-described koji preparation treatment and hydrolysis treatment, health promotion by means of at least one member of the group consisting of liver function improving constituents, cardiac function improving constituents, anti-inflammatory constituents, antifat constituents, antioxidation consititents and antimutagen constituents can be accomplished very effectively.
In the present invention, furthermore, intestine-regulating bacteria which are added following the initiation of the koji preparation treatment but prior to the completion of the hydrolysis treatment can be propagated very favorably, so that a health-promoting component consisting of such intestine-regulating bacteria can be included in large amounts in the final product, and can thus be used for intestinal regulation in single-stomached animals.
In particular, if intestine-regulating bacteria are added simultaneously with the inoculation of koji mold, these intestine-regulating bacteria will be propagated in large amounts in the process up to the completion of hydrolysis, so that the propagation of other undesirable organisms can be inhibited.
Furthermore, by the use of lactic acid bacteria which have an intestine-regulation action in single-stomached animals as the above-described intestine-regulating bacteria, an intestine-regulating action can be reliably manifested in single-stomached animals, and the propagation of other undesirable bacteria can be reliably inhibited by the lactic acid bacteria, which are acid-producing bacteria.
The product thus prepared can be utilized directly, and it also can be utilized in applied products which use this product as a raw material, e. g., food products, livestock feeds, pet foods or drug raw materials, etc., thus being superior in terms of all-purpose utility. Miso and soy sauce are foods with a high salt content since salt is added following the koji preparation step, thus having less all-purpose utility; moreover, the aging period of such food products following the koji preparation step is extremely long, thus having problems in productivity. To the contrary, according to the present invention, the product is easy to manufacture and realizes a saving in costs.
Since the product and preparation process of the present invention are constructed and act as described above, a health-promoting component can be produced in a product using beans as a raw material, by means of a koji preparation treatment and a hydrolysis treatment. In concrete terms, peptides, isoflavones, saponins and phytic acid, etc. are respectively converted into a health-promoting component such as isoflavone aglycones, saponii aglycones, myo-inositol and Maillard reaction products, etc. and are thus converted into a state which can be very easily absorbed by the digestive tracts of single-stomached animals. In the present invention, furthermore, the intestine-regulating bacteria added following the initiation of the above-described koji preparation treatment but prior to the completion of the hydrolysis treatment propagate so that a health-promoting component consisting of such intestine-regulating bacteria can be included in the product in large amounts, thus making it possible to achieve an intestine-regulating effect in the intestines of single-stomached animals. By using the product of the present invention which contains such a health-promoting component, health promotion by means of at least one member of the group consisting of liver function improving constituents, cardiac function improving constituents, anti-inflammatory constituents, antifat constituents, antioxidation consititents and antimutagen constituents and components which have an intestine-regulating effect in single-stomached animals can be accomplished very effectively. This product can be used directly xe2x80x9cas isxe2x80x9d, or the efficacy can be strengthened by extracting and concentrating the isoflavone aglycones, saponin aglycones, myo-inositol or Maillard reaction products, etc; in addition, this product can also be utilized in applied products which use this product as a raw material, e. g., food products, livestock feeds, pet foods or drug raw materials, etc. and is thus superior in terms of all-purpose utility. Furthermore, miso and soy sauce are foods with a high salt content, since salt is added following the koji preparation step, so that such food products lack all-purpose utility; moreover, the aging period of such food products following the koji preparation step is extremely long, so that there are problems in productivity. However, the product of the present invention is easy to manufacture at a low-cost.